One noteworthy omission from Microsoft's new Windows Phone 7 OS was Twitter integration, but not any more. Twitter introduced its official client for the platform, featuring the same swoosh user interface reviewers raved about last week. The app will be a welcome addition to Windows Phone 7's baby app library of around 1000 apps, with the first devices arriving in the U.S. on November 8.

Twitter's app for Windows Phone 7 devices uses Microsoft's Metro user interface, which uses so-called pivots to browse through information, making the app look unique in comparison to counterparts on Android or iOS (the iPad app is an improved replica of the new Twitter website).

The app includes most of the typical Twitter mobile app features, including the timeline, suggested users and messages lists. If you are not signed in into Twitter, the app lets you browse through top tweets, trends, and locations, just as you can on the web version; or search for certain topics and user names.

Because of the shortcoming of the first release of Windows Phone 7 software, the Twitter app won't be able to run in the background or integrate with your contact list initially. By contrast, Microsoft built Facebook functionality into Windows Phone 7 contacts, so you can see your friends' updates straight away from the People hub, and also integrated your friends list with your contacts (a blessing in disguise for some, as it could clutter your contacts with hundreds of Facebook friends).